无心弯管胎模设计

介绍了在使用无心弯管模弯曲管子的过程中存在的缺陷和采取的措施。通过采用增加弯管模具的夹紧块和镶块对毛坯的刚性约束来消除管内壁起褶的缺陷，采用固定数值法来解决管弯曲卸载后的弹性回跳的缺陷。介绍了在弯管模具设计中，前、后导向轮参数的选取方法以及根据管子的弯曲半径和弯管直径来分情况讨论其弧槽曲线的确定方法，避免在弯曲过程中弯管发生畸变，为设计弯管模具提供理论依据。     

ANALYSIS OF DEPOSITED PRODUCTS AND REANODIZED POROUS LUBRICATING FILM ON A1 AFTER(NH_4)_2MoS_4 SOLUTION TREATMENT

Observation was carried out of the structure of sulphuric,oxalic or phosphoricfilm on Al after treatment of reanodizing and electrolytic depositing lubricant in(NH_4)_2MoS_4 solution,as well as of the deposited products by means of EMPA,TEMand energy spectro-scopic analysis.The deposited products are mixture of compounds ofS and Mo rather than single MoS_2 and most of them dcposited near the surface layerof the film.Some regular long pores without barrier layer occurred in the film,but theregular fine channels without relation to the structural element parameters of originalanodized film were found in the thickened barrier layer of phosphoric film.Sulphur maybe remained as Mo sulphide in the film during heating under Ar protective environment.     

制备多物相AlTiC合金的Ti与C熔体反应法

将Ti与C同时加入Al熔体可制备出Ti与C摩尔比分别大于、等于、小于4的3种含不同物相的Al—TiC合金：Al—TiAl3-TiC、Al—TiC、Al-Al4C3-TiC。对纯铝的细化实验表明：不含过量Ti的后两种合金的细化效果相近，Al4C3在Al—TiC合金中的大量出现不会进一步降低合金的细化能力；含TiAl3的第一种合金的细化效率远高于后两者的；TiC物相在基体中以离散颗粒或聚集团形式在Al基体中分布；Al4C3相极脆，易与空气中的水蒸汽反应而分解。分析表明Ti与C在Al熔体中反应生成TiC是通过两条途径同时进行的：熔体中的固体C颗粒与溶解态的Ti直接反应；固体C颗粒和Al反应生成的A4C3与溶解态的Ti发生反应。     

HA/Ti composite for biomedical application by mechanical milling

In order to overcome the poor mechanical properties of HA and the low bioactivity of Ti,HA/Ti composites with various compositions were prepared by mechanical milling.The effects of milling condition and the composition on the microstructure,the density and the hardness of the composites were studied.The results show that during the ball milling process.Ti particles are refined and the homogeneity of the HA/Ti mixtures is improved;HA will partially decompose due to the existence of Ti and high sintering temperature.The microstructure of HA/Ti composites is highly dependent on the milling condition and the composition.In the microstructure.Ti phase connects to be a continuous network,and HA/Ti mixtures disperse in the network.The longer the milling time,the finer the network will be.The density of HA/T composites decreases with the content of HA increasing and the milling time prolonging,because HA deteriorates the sinterability of Ti.The hardness of HA/Ti composites increases firstly with the content of HA increasing,and then drops when the content of HA exceeds 30%.Addition of HA will strengthen the HA/T composite but will decrease the density of the composite,which accounts for the effect of HA on the hardness of the composites.     

牙科用钴铬合金的微束等离子焊接研究

探讨了以手工方式进行铸造钴铬合金口腔修复材料微束等离子电弧焊的可行性，试验过程电弧燃烧稳定，焊接接头充分熔透，母材与焊接连接良好，未见气孔，裂纹等缺陷。显微组织显示：焊缝与母材均为铸态的树枝状晶粒，几乎无焊接热影响区，焊接接头的电子能谱成分扫描、机械性能、显微硬度测试显示，接头成分均匀，焊缝与母材强度相当，微束等离子焊在口腔修复领域的应用前景明显优于其他熔化焊接方法。     

EFFECT OF PROGRESSIVE AGING TREATMENT ON THE PROPERTIES AND MICROSTRUCTUR

ＥＦＦＥＣＴＯＦＰＲＯＧＲＥＳＳＩＶＥＡＧＩＮＧＴＲＥＡＴＭＥＮＴＯＮＯＮＴＨＥＰＲＯＰＥＲＴＩＥＳＡＮＤＭＩＣＲＯＳＴＲＵＣＴＵＲＥＯＦＴＨＥＨＩＧＨ－ＨＡＲＤＥＬＡＳＴＩＣＮＩＣＫＥＬ－ＣＨＲＯＭＩＵＭ－ＡＬＵＭＩＮＩＵＭＡＬＬＯＹ￥ＬＩＵＧｕｉ...     

多目标优化理论在蜂窝夹芯结构设计中的应用

在确定了设计变量及目标函数的基础上,根据结构本身的要求,推导出用于多目标优化的5个约束条件.根据多目标优化理论,采用乘除法对蜂窝夹芯结构进行了评价函数的构造,并用VC语言编制了钢质蜂窝夹芯减振板结构的优化程序,该程序可实现结构尺寸及性能的优化,并计算出各目标函数的最终值.     

高速线材轧机锥套故障分析与改进

高速线材生产线精轧机、预精轧机使用的锥套，在材质、结构、处理工艺及生产操作上存在诸多不当之处，为此进行了多项改进，使锥套故障彻底排除，使用寿命达3～5月，而价格仅为进口件的1／3。     

FRACTURE BEHAVIOUR OF FUSED QUARTZ PARTICULATE COMPOSITES

本文研究了熔融石英颗粒复合材料的力学行为。结果表明,这种复合材料的弹性模量和断裂表面能与弥散于基体中的颗粒体积分数成正比,而断裂功随颗粒体积分数呈指数增加。认为颗粒与基体间弱界面的解聚是熔融石英颗粒复合材料韧化的原因。复合材料的弯曲强度与颗粒体积分数成反比,这是因为视为准裂纹的弱界面,其密度随颗粒体积分数而增加的缘故。抗热冲击损伤参数(R″″),随颗粒体积分数呈指数增加,颗粒体积分数越多,材料的抗热冲击性越好。     

基于均衡凝固理论设计球墨铸铁件冒口

介绍均衡凝固的基本原理，叙述铸件结构、冒口位置和冷铁对补缩的影响。结合铸件实例，说明合理设计冒口和利用冷铁使球铁铸件实现均衡凝固，防止缩孔、缩松的工艺方法。